This invention relates to a method for manufacturing bit patterned magnetic recording media using either surface acoustic wave devices or bulk waves. To increase the storage density of hard disk drives, bits need to be reduced in size, and be more closely packed on the magnetic disk. To avoid “magnetic cross-talk” between neighboring bits (interference of adjacent magnetic fields) when bits are recorded closer together, a physical separation needs to be created between adjacent bits. State-of-the-art manufacturing methods for these magnetic media such as nanolithography and nanoimprinting are expensive and tedious.
Typically, nanolithography is used to make a “master.” This master is then used to stamp several thousand of discrete track recording (“DTR”) or bit patterned media (“BPM”) disks. The grooves created between adjacent tracks or between adjacent bits are on the order of several nanometers to several tens of nanometers wide as well as deep. The lithography process is imperfect, and, thus, defects can exist on the surface of the master, which are then transferred to an imprinted disk. Creating a “master” is expensive. Applying nanolithography to a disk of 3.5″ (desktop products) or 2.5″ (laptop products) takes a lot of time. Additional problems exist with the state-of-the-art technology. The groove area needs to be filled with a non-magnetic medium. The magnetic read/write head is attached to a slider which “flies” over the magnetic medium at a spacing of 8-10 nm. Groove areas would periodically increase this spacing and give rise to dynamic instabilities in the flying behavior of the slider. Filling up nanometer sized grooves is, again, not straightforward to do, time consuming and costly.